Abstract Background The aim of this study was to evaluate the cost-effectiveness of traditional and endovenous treatments for patients with primary great saphenous varicose veins. Methods A Markov model was constructed to compare costs and quality-adjusted life years (QALYs) for great saphenous vein (GSV) reflux. Eight popular treatment strategies were compared up to 5 years. Estimates for the effectiveness of treatments were obtained from published randomized studies and cost values were obtained from published National Health Service (NHS) healthcare resource group tariffs and device manufacturers. Parameter uncertainty was tested using sensitivity analysis and Monte Carlo simulation. Results Ultrasound-guided foam sclerotherapy (UGFS) had the lowest initial cost, but a higher requirement for further interventions. Day-case surgery (with concomitant treatment of varicosities), endovenous laser ablation (EVLA) and radiofrequency ablation (RFA) performed in an outpatient or office setting (with staged treatment of varicosities) were likely to be cost-effective treatment strategies. The incremental cost-effectiveness ratio (ICER) for UGFS (versus conservative care), EVLA (versus UGFS) and RFA (versus EVLA) were £1366, £5799 and £17 350 per QALY respectively. The ICER for traditional surgery (performed on a day-case basis) was £19 012 compared with RFA. Other strategies were not cost-effective using the NHS threshold of £20 000 per QALY. Conclusion Day-case surgery or endovenous ablation using EVLA or RFA performed as an outpatient are likely to be cost-effective treatment strategies for patients with primary unilateral GSV reflux requiring treatment.